#!/bin/sh
a=10
b=20

#!
if [ $a != 10]
then
 echo "true"
else
 echo "false"
fi

#&&
if [[ $a == 10 && $b == 20 ]]
then
 echo "true"
else
 echo "false"
fi
#-a
if [ $a == 10 -a $b == 20 ]
then
 echo "true"
else
 echo "false"
fi

#||
if [[ $a == 10 || $b == 100 ]]
then
 echo "true"
else
 echo "false"
fi
#-o
if [ $a == 10 -o $b == 100 ]
then
 echo "true"
else
 echo "false"
fi
